Cod sursa(job #3233200)

Utilizator MirceaDonciuLicentaLicenta Mircea Donciu MirceaDonciuLicenta Data 2 iunie 2024 19:18:39
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.56 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <limits>

using namespace std;

const int INF = numeric_limits<int>::max();

void dijkstra(int N, const vector<vector<pair<int, int>>>& adj, vector<int>& dist) {
    dist[1] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    pq.push({0, 1});  // (distance, node)

    while (!pq.empty()) {
        int u = pq.top().second;
        int d = pq.top().first;
        pq.pop();

        if (d > dist[u]) continue;

        for (const auto& edge : adj[u]) {
            int v = edge.first;
            int length = edge.second;

            if (dist[u] + length < dist[v]) {
                dist[v] = dist[u] + length;
                pq.push({dist[v], v});
            }
        }
    }
}

int main() {
    ifstream infile("dijkstra.in");
    ofstream outfile("dijkstra.out");

    if (!infile || !outfile) {
        cerr << "Error opening file" << endl;
        return 1;
    }

    int N, M;
    infile >> N >> M;

    vector<vector<pair<int, int>>> adj(N + 1);

    for (int i = 0; i < M; ++i) {
        int A, B, C;
        infile >> A >> B >> C;
        adj[A].push_back({B, C});
    }

    vector<int> dist(N + 1, INF);
    dijkstra(N, adj, dist);

    for (int i = 2; i <= N; ++i) {
        if (dist[i] == INF) {
            outfile << "0 ";
        } else {
            outfile << dist[i] << " ";
        }
    }
    outfile << endl;

    infile.close();
    outfile.close();

    return 0;
}